The only daughter of Greek shipping tycoon Aristotle Onassis, Christina Onassis's tempestuous personal life, which included four marriages, diverted attention from her role in the business world. Born in New York City, Onassis began working in her father's business as a secretary and, after his death, she inherited half of his estimated $1 billion estate, the other half going to create the Alexander Onassis foundation. Onassis sat on the foundation's board and served as its president. Although she was separated from her fourth husband and lived a “jet-setting” lifestyle, Onassis regularly conducted three to four hours of business daily no matter her location. She suffered a fatal heart attack in 1988, leaving one child, a daughter named Athena, who became the sole heir to the Onassis fortune.